'\" te
.\" Copyright (c) 2007, Sun Microsystems, Inc., All Rights Reserved
.\" The contents of this file are subject to the terms of the Common Development and Distribution License (the "License").  You may not use this file except in compliance with the License.
.\" You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing.  See the License for the specific language governing permissions and limitations under the License.
.\" When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE.  If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
.TH KICONV 9F "Oct 16, 2007"
.SH NAME
kiconv \- buffer-based code conversion function
.SH SYNOPSIS
.nf
#include <sys/types.h>
#include <sys/errno.h>
#include <sys/sunddi.h>



\fBsize_t\fR \fBkiconv\fR(\fBkiconv_t\fR \fIcd\fR, \fBchar **\fR\fIinbuf\fR, \fBsize_t *\fR\fIinbytesleft\fR,
     \fBchar **\fR\fIoutbuf\fR, \fBsize_t *\fR\fIoutbytesleft\fR, \fBint *\fR\fIerrno\fR);
.fi

.SH INTERFACE LEVEL
illumos DDI specific (illumos DDI).
.SH PARAMETERS
The parameters for the \fBkiconv\fR function are as follows:
.sp
.ne 2
.na
\fB\fIcd\fR\fR
.ad
.RS 16n
Code conversion descriptor indicating the code conversion and conversion state.
.RE

.sp
.ne 2
.na
\fB\fIinbuf\fR\fR
.ad
.RS 16n
Points to an address of a buffer containing a sequence of character bytes in
\fBfromcode\fR codeset to be converted. After the conversion, the variable is
updated to point to the byte following the last byte that was successfully used
in the conversion.
.RE

.sp
.ne 2
.na
\fB\fIinbytesleft\fR\fR
.ad
.RS 16n
As an input parameter, the number of bytes to be converted in \fIinbuf\fR. As
an output parameter, the number of bytes in \fIinbuf\fR still not converted
after the conversion.
.RE

.sp
.ne 2
.na
\fB\fIoutbuf\fR\fR
.ad
.RS 16n
Points to an address of a buffer where converted character bytes in
\fBtocode\fR codeset can be saved. After the conversion, the variable is
updated to point to the byte following the last byte of converted output data.
.RE

.sp
.ne 2
.na
\fB\fIoutbytesleft\fR\fR
.ad
.RS 16n
As an input parameter, the number of available bytes at \fIoutbuf\fR where
converted character bytes can be saved. As an output parameter, the number of
bytes still available at \fIoutbuf\fR after the conversion.
.RE

.sp
.ne 2
.na
\fB\fIerrno\fR\fR
.ad
.RS 16n
Indicates the error when conversion is not completed or failed. The following
are possible values:
.sp
.ne 2
.na
\fB\fBEILSEQ\fR\fR
.ad
.RS 13n
The input conversion was stopped due to an input byte that does not belong to
the input codeset.
.RE

.sp
.ne 2
.na
\fB\fBE2BIG\fR\fR
.ad
.RS 13n
The input conversion was stopped due to lack of space in the output buffer.
.RE

.sp
.ne 2
.na
\fB\fBEINVAL\fR\fR
.ad
.RS 13n
The input conversion was stopped due to an incomplete character or shift
sequence at the end of the input buffer.
.RE

.sp
.ne 2
.na
\fB\fBEBADF\fR\fR
.ad
.RS 13n
The \fIcd\fR input parameter is not a valid open code conversion descriptor.
.RE

.RE

.SH DESCRIPTION
The \fBkiconv()\fR function converts the sequence of characters from one
\fBcodeset\fR, in the array specified by \fIinbuf\fR, into a sequence of
corresponding characters in another \fBcodeset\fR, in the array specified by
\fIoutbuf\fR. The \fBcodesets\fR are those specified in the \fBkiconv_open()\fR
call that returned the code conversion descriptor, \fIcd\fR. The \fIinbuf\fR
parameter points to a variable that points to the first character in the input
buffer and \fIinbytesleft\fR indicates the number of bytes to the end of the
buffer to be converted. The \fIoutbuf\fR parameter points to a variable that
points to the first available byte in the output buffer and \fIoutbytesleft\fR
indicates the number of the available bytes to the end of the buffer.
.sp
.LP
For state-dependent encodings, the conversion descriptor \fIcd\fR is placed
into its initial shift state by a call for which \fIinbuf\fR is a null pointer,
or for which \fIinbuf\fR points to a null pointer. When \fBkiconv()\fR is
called in this way, and if \fIoutbuf\fR is not a null pointer or a pointer to a
null pointer, and \fIoutbytesleft\fR points to a positive value, \fBkiconv()\fR
places, if any, into the output buffer, the byte sequence to change the output
buffer to its initial shift state. If the output buffer is not large enough to
hold the entire reset sequence, \fBkiconv()\fR fails and sets \fIerrno\fR to
\fBE2BIG\fR. Subsequent calls with \fIinbuf\fR as other than a null pointer or
a pointer to a null pointer cause the conversion to take place from the current
state of the conversion descriptor.
.sp
.LP
If a sequence of input bytes does not form a valid character in the specified
\fBcodeset\fR, conversion stops after the previous successfully converted
character. If the input buffer ends with an incomplete character or shift
sequence, conversion stops after the previous successfully converted bytes. If
the output buffer is not large enough to hold the entire converted input,
conversion stops just prior to the input bytes that would cause the output
buffer to overflow. The variable pointed to by \fIinbuf\fR is updated to point
to the byte following the last byte that was successfully used in the
conversion. The value pointed to by \fIinbytesleft\fR is decremented to reflect
the number of bytes still not converted in the input buffer. The variable
pointed to by \fIoutbuf\fR is updated to point to the byte following the last
byte of converted output data. The value pointed to by \fIoutbytesleft\fR is
decremented to reflect the number of bytes still available in the output
buffer. For state-dependent encodings, the conversion descriptor is updated to
reflect the shift state in effect at the end of the last successfully converted
byte sequence.
.sp
.LP
If \fBkiconv()\fR encounters a character in the input buffer that is legal, but
for which an identical character does not exist in the target \fBcodeset\fR,
\fBkiconv()\fR performs an implementation-defined conversion (that is, a
non-identical conversion) on this character.
.SH RETURN VALUES
The \fBkiconv()\fR function updates the variables pointed to by the parameters
to reflect the extent of the conversion and returns the number of non-identical
conversions performed. If the entire string in the input buffer is converted,
the value pointed to by \fIinbytesleft\fR is 0. If the input conversion is
stopped due to any conditions mentioned above, the value pointed to by
\fIinbytesleft\fR is non-zero and \fIerrno\fR is set to indicate the condition.
If such and other error occurs, \fBkiconv()\fR returns (\fBsize_t\fR)-1 and
sets \fIerrno\fR to indicate the error.
.SH CONTEXT
\fBkiconv()\fR can be called from user or interrupt context.
.SH EXAMPLES
\fBExample 1 \fRPerforming a Simple Conversion
.sp
.LP
The following example shows how to perform a simple conversion using
\fBkiconv()\fR with a limited size of output buffer:

.sp
.in +2
.nf
#include <sys/types.h>
#include <sys/errno.h>
#include <sys/sunddi.h>

int
doconversion(char *fromcode, char *tocode, char *inbuf, char *outbuf,
                size_t inlen, size_t *outlen)
{
        kiconv_t cd;
        size_t ileft, ret;
        int err;

        cd = kiconv_open((const char *)tocode, (const char *)fromcode);
        if (cd == (kiconv_t)-1) {
               /* Cannot open conversion. */
               return (-1);
        }

        ret = kiconv(cd, &inbuf, &inlen, &outbuf, outlen, &err);
        if (ret == (size_t)-1)
                goto doconv_error_return;

        /*
         * Reset the conversion descriptor. This will also
         * make sure to write to output buffer any saved bytes
         * in the conversion descriptor state.
         */
        ileft = 0;
        ret = kiconv(cd, (char *)NULL, &ileft, &outbuf, outlen, &err);
        if (ret == (size_t)-1)
                goto doconv_error_return;

        (void) kiconv_close(cd);

        return (0);

doconv_error_return:
        (void) kiconv_close(cd);

        /* Need more output buffer. */
        if (err == E2BIG)
                return (-2);

        /* Illegal sequence? */
        if (err == EILSEQ)
                return (-3);

        /* Incomplete character? */
        if (err == EINVAL)
                return (-4);

        /*
         * Bad code conversion descriptor or any other unknown error.
         */
        return (-5);
}
.fi
.in -2

.SH ATTRIBUTES
See \fBattributes\fR(7) for descriptions of the following attributes:
.sp

.sp
.TS
box;
c | c
l | l .
ATTRIBUTE TYPE	ATTRIBUTE VALUE
_
Interface Stability	Committed
.TE

.SH SEE ALSO
.BR iconv (3C),
.BR iconv_close (3C),
.BR iconv_open (3C),
.BR u8_strcmp (3C),
.BR u8_textprep_str (3C),
.BR u8_validate (3C),
.BR uconv_u16tou32 (3C),
.BR uconv_u16tou8 (3C),
.BR uconv_u32tou16 (3C),
.BR uconv_u32tou8 (3C),
.BR uconv_u8tou16 (3C),
.BR uconv_u8tou32 (3C),
.BR attributes (7),
.BR kiconv_close (9F),
.BR kiconv_open (9F),
.BR kiconvstr (9F),
.BR u8_strcmp (9F),
.BR u8_textprep_str (9F),
.BR u8_validate (9F),
.BR uconv_u16tou32 (9F),
.BR uconv_u16tou8 (9F),
.BR uconv_u32tou16 (9F),
.BR uconv_u32tou8 (9F),
.BR uconv_u8tou16 (9F),
.BR uconv_u8tou32 (9F)
.sp
.LP
The Unicode Standard:
.sp
.LP
http://www.unicode.org/standard/standard.html
.SH NOTES
The \fBiconv\fR(3C) man page also has a good example code that can be
referenced.
